How do you encourage babies to chew? I tried Erin with some toast and banana this morning (she's had toast before and was happy to suck on it) but she must have sucked a lump off it today and it got caught in her throat. It was only after I'd whacked her on the back that it dislodged and she spat it out. When and how do they actually learn to chew? Is there anything I could be doing to help her?